JP7352879B2 - Base station and communication method - Google Patents

Description

The present disclosure relates to a base station and a communication method.

Private LTE systems, in which companies introduce LTE (Long Term Evolution) for their own networks, are attracting attention. An independent LTE system is also called a private LTE system. Such a private LTE system is also expected to be an alternative to the existing private PHS (Personal Handy-phone System) system. This PHS system is based on the TDD (time division duplex) system.

A private LTE system that does not require a license and is institutionalized in Japan in 2017 is based on the sXGP (shared eXtended Global Platform) standard, which is based on the TD-LTE (Time Division - LTE) system. There is a system. In contrast to the PHS system, which mainly uses voice calls, the sXGP system allows data communication in addition to voice calls, so it can be used with general smartphones. The frequency band used in the sXGP system is the same 1.9 GHz band as "Band 39" internationally defined for LTE, and overlaps with a part of the frequency band used in the PHS system.

If the existing private PHS system is large-scale, it is difficult to replace the entire in-house telephone network from the private PHS system to the private sXGP system at once, so limit the scope of replacement and replace the PHS system with the sXGP system in order. It turns out. In order to guarantee business continuity until system switching is completed, it is necessary to share the PHS network and sXGP network for a certain period of time. However, since the sXGP system uses a frequency band that overlaps with the PHS system, it is difficult to jointly operate the sXGP system and the PHS system in the same area due to mutual interference.

In Prior Art Document 1, a guard period (GP) in a special subframe in the TD-LTE frame format is used to connect the downlinks of TD-LTE and PHS. ) and uplink (UL) to reduce interference.

Furthermore, in Prior Art Document 1, in a downlink subframe of a TD-LTE system corresponding to a downlink slot in which a control channel necessary for the operation of a PHS system (hereinafter referred to as "PHS control channel") is transmitted, Interference is reduced by stopping data transmission.

JP 2018-19233 Publication

The PHS control channel is transmitted in specific time slots on two channels that interfere with part of the TD-LTE (sXGP) frequency band. Therefore, if transmission of a specific subframe of the TD-LTE method is stopped in all frequency bands as in Patent Document 1, the frequency band (in other words, resource block) of the sXGP method that does not interfere with the PHS control channel is The transmission of the data will also be stopped, resulting in poor resource usage efficiency.

Non-limiting embodiments of the present disclosure contribute to providing a technique for suppressing mutual interference while improving resource utilization efficiency.

The base station in the present disclosure provides a second communication method using a second communication method that uses a second frequency band that is common to a part of the first frequency band used in the first communication method used in the first communication system. A base station of the system includes an estimator that estimates slot timing of a downlink control channel transmitted from the base station of the first communication system at a predetermined channel frequency and a predetermined period; In the resources of the second communication method that correspond to the slot timing on the time axis, a scheduling unit that performs scheduling to allocate data to resource blocks that do not overlap with the predetermined channel frequency, and a transmitting and receiving unit that performs transmission and reception based on the scheduling. and,
Equipped with.

Note that these comprehensive or specific aspects may be realized by a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium. It may be realized by any combination of the following.

According to the present invention, when two systems that share a part of the frequency band coexist, such as an sXGP system and a PHS system, mutual interference can be suppressed while improving resource utilization efficiency.

Further advantages and effects of an embodiment of the present disclosure will become apparent from the description and drawings. Such advantages and/or effects may be provided by each of the embodiments and the features described in the specification and drawings, but not all need to be provided in order to obtain one or more of the same features. There isn't.

Diagram showing the relationship between the frequency bands used by the PHS method and the frequency bands used by the sXGP method A diagram showing the transmission power of a PHS control channel transmitted by a plurality of PHS base stations according to Embodiment 1 of the present disclosure A diagram illustrating a method for combining received power of PHS control channels in a TD-LTE base station according to Embodiment 1 of the present disclosure. A diagram showing data allocation in a TD-LTE base station according to Embodiment 1 of the present disclosure A diagram showing a flow of operation of a TD-LTE base station according to Embodiment 1 of the present disclosure Configuration diagram of a TD-LTE base station according to Embodiment 1 of the present disclosure A diagram showing a method for detecting slot timing of a PHS control channel in a TD-LTE base station according to Embodiment 2 of the present disclosure. A diagram showing a PHS frame timing detection method in a control server according to Embodiment 2 of the present disclosure Sequence diagram showing operations between a TD-LTE base station and a control server according to Embodiment 2 of the present disclosure A diagram showing the configuration of a TD-LTE base station according to Embodiment 2 of the present disclosure Configuration diagram of a control server according to Embodiment 2 of the present disclosure A diagram showing a method of notifying a transmission timing shift amount by a base station equipped with a PHS control channel receiver according to Embodiment 3 of the present disclosure. Sequence diagram showing operations between a base station, a base station equipped with a PHS control channel receiver, and a control server according to Embodiment 3 of the present disclosure Configuration diagram of a base station equipped with a PHS control channel receiver according to Embodiment 3 of the present disclosure Configuration diagram of a control server when using a base station equipped with a PHS control channel receiver according to Embodiment 3 of the present disclosure A diagram showing a method of notifying a transmission timing shift amount by a TD-LTE timing shift amount measuring device according to Embodiment 4 of the present disclosure. Sequence diagram showing operations between a timing shift amount measuring device, a base station, and a control server according to Embodiment 4 of the present disclosure Configuration diagram of a base station according to Embodiment 4 of the present disclosure Configuration diagram of a timing shift amount measuring device according to Embodiment 4 of the present disclosure A diagram showing an example of residual interference from the TD-LTE system to the PHS system according to Embodiment 5 of the present disclosure A diagram showing residual interference to a PHS terminal directly under a TD-LTE base station according to Embodiment 5 of the present disclosure A diagram showing the effect of interference reduction due to transmission power reduction of a TD-LTE base station according to Embodiment 5 of the present disclosure A diagram showing received power after combining PHS control channels measured at a TD-LTE base station according to Embodiment 5 of the present disclosure Configuration diagram of a base station according to Embodiment 5 of the present disclosure Flowchart of operation of base station according to Embodiment 5 of the present disclosure

Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of well-known matters or redundant explanations of substantially the same configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

FIG. 1 is a diagram showing the relationship between the frequency bands used by the PHS system and the frequency bands used by the sXGP system. As shown in FIG. 1, the frequency band 101 of the PHS system ranges from 1893.5 MHz (102) to 1906.1 MHz (103). The PHS control channel is transmitted using the 12th channel (CH12) and the 18th channel (CH18). Specifically, the PHS control channel uses CH12 with a frequency of 1898.45 MHz (A) and CH18 with a frequency of 1900.25 MHz (B). On the other hand, the sXGP 5 MHz system uses a frequency band 104 with a center frequency of 1899.1 MHz and a bandwidth of 5.0 MHz. In this way, the frequencies of CH12 and CH18 used in the PHS control channel overlap with the frequency band of the sXGP system. Therefore, mutual interference occurs at the timing and frequency at which the PHS control channels are transmitted.

In TD-LTE system (sXGP system) wireless communication, an LTE radio frame (RF: Radio Frame) with a predetermined period (Tf = 10ms), which is one unit on the time axis, is divided into 10 1ms subframes (SF: Subframe). One subframe (SF) is composed of two time slots (TS). That is, one LTE radio frame is composed of 10 subframes (in other words, 20 time slots). In LTE, the area surrounded by 12 subcarriers on the frequency axis (the subcarrier interval is 15kHz in Release 8) and one slot on the time axis is called a resource block (RB), and is used for allocation (scheduling) to users. ) is performed in this temporally continuous nRB unit (n is an integer that varies depending on the band).

A PHS radio frame (RF) with a predetermined period (Tf=5 ms), which is one unit on the time axis in PHS wireless communication, is composed of eight time slots (TS) of 0.625 ms.

(Embodiment 1)
Embodiment 1 according to the present disclosure will be described using FIGS. 2 to 5.

2A and 2B are diagrams illustrating a method for estimating transmission timing of a downlink PHS control channel according to Embodiment 1 of the present disclosure. More specifically, FIG. 2A is a diagram showing the transmission power of a PHS control channel transmitted by a plurality of PHS base stations according to Embodiment 1 of the present disclosure. In FIG. 2A, three TD-LTE base stations 201, 203, and 205 and three PHS base stations 202, 204, and 206 are illustrated as examples.

Note that "TD-LTE base station" may be mutually replaced with other terms such as "base station" or "sXGP base station."

As shown in the graph in frame 211 of FIG. 2A, the PHS base station 202 transmits the PHS control channel in one specific slot every period T (for example, superframe=125 ms). Similarly, the PHS base station 204 transmits a PHS control channel every period T, as shown in the graph in box 212 of FIG. 2A. Further, the PHS base station 206 transmits the PHS control channel every period T, as shown in the graph in the frame 213 in FIG. 2A. Note that the vertical axis of each graph in FIG. 2A is the transmission power of the PHS control channel of each PHS base station 202, 204, 206, and the horizontal axis is time. Furthermore, the transmission power shown in FIG. 2A represents the transmission power of the PHS control channel in one of the two PHS transmission channels (ie, CH12 and CH18).

FIG. 2B is a diagram illustrating a method for combining received power of PHS control channels in a TD-LTE base station according to Embodiment 1 of the present disclosure. FIG. 2B describes a method for combining received powers of PHS control channels in TD-LTE base station 205 among the three TD-LTE base stations 201, 203, and 205 shown in FIG. 2A.

In order to know the transmission timing of the PHS control channel of the PHS base station, the TD-LTE base station 205 uses the frame of FIG. 2B at two predetermined frequencies of the PHS control channel (hereinafter also referred to as "PHS control channel frequencies"). As shown in 250, the received power is divided into fixed periods, combined in accordance with the leading timing, and the transmission timing of the signal whose combined signal power is equal to or higher than the threshold is determined by the slot timing (transmission timing) of the PHS downlink control channel. period).

Specifically, the TD-LTE base station 205 measures the received power of the PHS control channel every period T, as shown in the upper diagram in the frame 250. In the example shown in this figure, the received power of the PHS control channel is measured at each of four periods T (261, 262, 263, 264).

By setting a period that is an integral multiple (in the example of FIG. 2B, twice (2T)) of the transmission period of the PHS control channel as this fixed period, it becomes easy to exclude non-periodic noise. Specifically, in the upper diagram of Figure 2B, when the received power is combined every two cycles (2T) (2T (271), 2T (272)), the vertical axis changes as shown in the lower diagram of Figure 2B. A graph with time (283) on the horizontal axis is created using the combined received power (273). In this figure, the received power portion below the predetermined threshold (284) is assumed to be noise, and therefore does not need to be included in the estimation of the slot timing. In the example of FIG. 2B, the received power portion indicated by 282 is excluded from slot timing estimation as noise. In addition, in the combined received power (273), the received power portion (281) without periodicity is also assumed to be noise and is therefore excluded from slot timing estimation. Then, the TD-LTE base station 205 estimates the reception timing of the received power portion that is equal to or higher than a predetermined threshold and has periodicity as the slot timing of the PHS control channel.

Note that, similarly to the TD-LTE base station 205, the TD-LTE base stations 201 and 203 also estimate the slot timing of the downlink PHS control channel.

As mentioned above, the downlink PHS control channel is transmitted at predetermined intervals, but unlike the downlink PHS control channel, the uplink PHS control channel is not transmitted at every predetermined interval. . Furthermore, since the PHS terminal is farther from the TD-LTE base station than the PHS base station, the received power of the PHS control channel is small. For these reasons, even if the received power of uplink PHS control channels is combined, the combined received power is less than a predetermined threshold, and slot timing cannot be estimated.

It is also possible to estimate slot timing by making a threshold judgment for one received power without combining the received powers of uplink control channels as described above, but the slot timing estimation accuracy is It gets lower.

Therefore, in this embodiment, since the PHS uplink control channel is transmitted a predetermined number of slots after the slot timing of the downlink control channel on the same two predetermined frequencies as the downlink, the estimated downlink The slot timing of the uplink control channel is estimated based on the slot timing of the control channel.

FIG. 3 is a diagram showing data allocation in a TD-LTE base station according to Embodiment 1 of the present disclosure. As shown in FIG. 3, the TD-LTE base station uses the estimated downlink and uplink PHS control channel slot timings and frequency resources that overlap with predetermined frequencies of the PHS control channel (in other words, CH12 and CH18 ), scheduling is performed that does not allocate downlink or uplink data.

Specifically, in the graph shown in FIG. 3 in which the vertical axis is the combined power 301 in the PHS control channel (CH18) and the horizontal axis is time, the received power of some PHS control channels exceeds the threshold 302. ing. The TD-LTE base station does not allocate downlink data to the resource (resource block) that corresponds to the frequency of the PHS control channel in a slot in which the combined received power 301 of this PHS control channel exceeds the threshold 302. . FIG. 3 shows a resource 311 in CH18 to which downlink data is not allocated based on estimation for CH18, and it can be seen that it is synchronized with the combined power in the PHS control channel that exceeds the threshold 302. Note that estimation may be performed in the same manner for CH12, and scheduling may be performed in which downlink data is not allocated, as shown in resource 311 for CH12 in FIG.

Regarding the uplink, the TD-LTE base station does not allocate uplink data to a resource (subframe) corresponding to a predetermined number of slots after the resource to which no downlink data was allocated. FIG. 3 shows a resource 312 to which uplink data is not allocated. As shown in FIG. 3, it can be seen that the transmission slot of the uplink PHS control channel is delayed by a predetermined number of slots from the transmission slot of the downlink PHS control channel.

In this way, in this embodiment, the TD-LTE base station avoids allocating downlink and uplink data to both PHS control channels CH18 and CH12 at the slot timing of the PHS control channel. do. Furthermore, for channels other than CH18 and CH12, the TD-LTE base station allocates downlink and uplink data also at the slot timing of the PHS control channel.

In addition, in order to increase the resource utilization efficiency of the TD-LTE base station, allocation to only the frequency resource that overlaps with the frequency of one of the two control channels of PHS (i.e., CH12 or CH18) is limited to the PHS control channel. Scheduling may be performed to avoid this at slot timing.

FIG. 4 is a diagram showing a flow of operations of the TD-LTE base station according to Embodiment 1 of the present disclosure. First, the TD-LTE base station measures the received power at the PHS control channel frequency (ST401).

Next, the TD-LTE base station combines the plurality of measured received powers (ST402).

Next, the TD-LTE base station estimates the transmission timing of the downlink PHS control channel based on the combined received power (ST403).

Next, the TD-LTE base station estimates the transmission timing of the uplink PHS control channel based on the estimated transmission timing of the downlink PHS control channel (ST404).

Next, the TD-LTE base station performs TD-LTE uplink and downlink scheduling based on the estimated transmission timing of the PHS control channel (ST405).

FIG. 5 is a configuration diagram of a TD-LTE base station according to Embodiment 1 of the present disclosure. The TD-LTE base station 201 includes an antenna 501, a transmitting/receiving section 502, a received power measuring section 503, a received power combining section 504, a PHS control channel timing estimating section 505, a scheduling section 506, and a data processing section 507. , is provided.

The transmitting/receiving unit 502 transmits and receives signals at the PHS control channel frequency via the antenna 501. Received power measuring section 503 measures the received power of the signal received by transmitting/receiving section 502.

Received power combining section 504 combines the received powers of the signals received from received power measuring section 503 at a plurality of PHS control channel frequencies.

PHS control channel timing estimating section 505 estimates the timing of the PHS control channel based on the magnitude relationship between the combined received power and the threshold received from received power combining section 504.

Scheduling section 506 performs a TD-LTE transmission schedule based on the estimated value of PHS control channel timing received from PHS control channel timing estimation section 505 and the data received from data processing section 507.

As explained above, according to the first embodiment, among the resources corresponding to the slot timing of the PHS control channel, data is not allocated to resources that overlap with the PHS control channel, and data is not allocated to resources that do not overlap with the PHS control channel. By performing scheduling that allocates , it is possible to suppress mutual interference while improving usage efficiency. Furthermore, by using the received power of the PHS control channel signal, the transmission timing of the PHS control channel can be estimated without using a PHS control channel receiver. Furthermore, it is possible to avoid interference not only with the downlink PHS control channel but also with the uplink PHS control channel.

(Embodiment 2)
Embodiment 2 according to the present disclosure will be described with reference to FIGS. 6 to 10.

FIG. 6 is a diagram illustrating a method for detecting slot timing of a PHS control channel in a TD-LTE base station according to Embodiment 2 of the present disclosure. The configuration of Embodiment 1 described above makes it possible to schedule the TD-LTE data channel while avoiding the allocation of downlink and uplink data using the slot timing of the PHS control channel. In order to transmit and receive data between the base station and the terminal, it is more preferable to synchronize timing between the PHS base station and the TD-LTE base station. For this purpose, it is necessary to estimate the PHS frame timing.

As shown in FIG. 6, TD-LTE base stations perform synchronization between base stations using position information such as GPS (Global Positioning System). Next, the received PHS control channel is divided into sections every 10 ms of the TD-LTE radio frame (sections separated by the vertical broken lines of the combined received power 601 shown in FIG. 6). Then, the TD-LTE base station further combines radio frames including PHS control channels with combined received power exceeding the threshold 602 (dotted chain line) obtained in Embodiment 1 to obtain combined received power 604. A combined radio frame 605 with a period of 10 ms is created.

FIG. 7 is a diagram illustrating a PHS frame timing detection method in a control server according to Embodiment 2 of the present disclosure. In FIG. 7, one control server 701, four TD-LTE base stations 721, 723, 725, 727, and four PHS base stations 722, 724, 726, 728 are shown. Control server 701 is also called a control station.

As shown in FIG. 7, each TD-LTE base station 721, 723, 725, 727 transmits power information (711, 712, 713, 714) indicating received power combined on a wireless frame basis to a control device connected via a LAN or the like. Notify the server 701. Next, the control server 701 further combines the received power combined in radio frame units at each TD-LTE base station to detect the time for all 4 slots for PHS downlink (702), and The downlink slot is estimated to be the beginning 703 of the PHS frame. This allows the control server 701 to detect how much the PHS frame timing deviates from the TD-LTE wireless frame timing. Next, the control server 701 notifies each TD-LTE base station 721, 723, 725, and 727 of the shift amount of the transmission timing on the TD-LTE side. Thereby, timing synchronization between the PHS base stations 722, 724, 726, and 728 and the TD-LTE base stations 721, 723, 725, and 727 can be realized.

FIG. 8 is a sequence diagram showing the operation between the TD-LTE base station 721 and the control server 701 shown in FIG.

As shown in FIG. 8, the TD-LTE base station 721 measures the received power of the signal at the PHS control channel frequency (ST801). Next, the measured received powers are combined based on the TD-LTE radio frame timing (ST802).

Next, each TD-LTE base station 721 transmits power information indicating the combined received power to the control server 701 (ST803).

Next, the control server 701 combines the power information received from each TD-LTE base station based on the TD-LTE radio frame timing (ST804).

Next, control server 701 estimates PHS frame timing based on the combined power information (ST805). Next, the control server 701 calculates the TD-LTE timing shift amount based on the estimated PHS frame timing (ST806), and transmits the timing shift amount to each TD-LTE base station 721 (ST807).

Next, each TD-LTE base station 721 shifts the transmission timing based on the timing shift amount received from the control server 701 (ST808).

FIG. 9 is a diagram showing the configuration of a TD-LTE base station according to Embodiment 2 of the present disclosure.

TD-LTE base station 721 includes an antenna 901, a transmitting/receiving section 902, a received power measuring section 903, a received signal combining section 904, a network section 905, and a frame timing control section 906.

The transmitting/receiving unit 902 transmits and receives signals at the PHS control channel frequency via the antenna 901. The received power measuring section 903 measures the power of the radio wave (wireless signal) received by the transmitting/receiving section 902. A received signal combining section 904 combines received powers based on TD-LTE radio frame timing and generates power information. The network unit 905 transmits the power information generated by the received signal combining unit 904 to the control server 701. The frame timing control unit 906 shifts the transmission timing of the base station 721 based on the timing shift amount received from the control server 701 via the network unit 905.

FIG. 10 is a configuration diagram of a control server according to Embodiment 2 of the present disclosure. The control server 701 includes a network section 1001, a PHS frame timing detection section 1002, and a timing shift amount calculation section 1003.

Network unit 1001 receives power information from each TD-LTE base station via the network. PHS frame timing detection section 1002 receives power information from network section 1001, combines multiple pieces of power information based on TD-LTE radio frame timing, and detects PHS frame timing. The timing shift amount calculating section 1003 calculates the timing shift amount of TD-LTE based on the detected PHS frame timing, and transmits the timing shift amount to each TD-LTE base station via the network section 1001.

As explained above, according to the second embodiment, PHS frame timing is detected without using a PHS control channel receiver, and inter-base station synchronization between a PHS base station and a TD-LTE base station is realized. can do.

Note that the TD-LTE base station described in Embodiment 1 may include part or all of the configuration of the TD-LTE base station described in Embodiment 2 using FIG. 9 and the like.

(Embodiment 3)
Embodiment 3 according to the present disclosure will be described using FIGS. 11 to 14.

FIG. 11 is a diagram illustrating a method of notifying a transmission timing shift amount by a base station equipped with a PHS control channel receiver according to Embodiment 3 of the present disclosure.

In FIG. 11, a control server 1102 is connected to multiple PHS base stations 1104, 1106, 1108, 1110 and multiple TD-LTE base stations 1103, 1105, 1107, 1109 via a network. The TD-LTE base station 1105 is a PHS control channel receiver-equipped base station equipped with a PHS control channel receiver.

The PHS control channel receiver-equipped base station 1105 receives the PHS control channel, detects the timing of the PHS frame, calculates the shift amount of the transmission timing of the TD-LTE base station, and transmits the calculated timing shift amount to the control server. 1102. The control server 1102 transmits the timing shift amount received from the PHS control channel receiver-equipped base station 1105 to each TD-LTE base station 1103, 1105, 1107, and 1109.

Note that in this embodiment, as shown in FIG. 11, only one TD-LTE base station is equipped with a PHS control channel receiver, and the other TD-LTE base stations are not equipped with a PHS control channel receiver. It may be. The PHS control channel receiver-equipped base station 1105 may calculate the shift amount of the TD-LTE transmission timing, and notify each base station 1103, 1105, 1107, and 1109 of the timing shift amount via the control server 1102. .

FIG. 12 is a sequence diagram showing operations between a base station, a base station equipped with a PHS control channel receiver, and a control server according to Embodiment 3 of the present disclosure.

First, the PHS control channel receiver-equipped base station 1105 receives a PHS frame on the frequency used by the PHS control channel, and detects the PHS frame timing from the received PHS frame (ST1201). Next, the PHS control channel receiver equipped base station 1105 calculates the TD-LTE timing shift amount based on the detected PHS frame timing (ST1202). Next, the PHS control channel receiver-equipped base station 1105 transmits the calculated TD-LTE timing shift amount to the control server 1102 (ST1203).

The control server 1102 transmits the timing shift amount received from the PHS control channel receiver equipped base station 1105 to the PHS control channel receiver equipped base station 1105 (ST1204), and similarly transmits the timing shift amount to other TD-LTE base stations. 1103 (ST1205). Note that the control server does not need to transmit the timing shift amount to the PHS control channel receiver-equipped base station 1105.

PHS control channel receiver equipped base station 1105 shifts the transmission timing of PHS control channel receiver equipped base station 1105 based on the timing shift amount received from control server 1102 (ST1206). Note that the PHS control channel receiver equipped base station 1105 may shift the transmission timing of the PHS control channel receiver equipped base station 1105 based on the timing shift amount calculated by itself.

Base station 1103 shifts the transmission timing of base station 1103 based on the timing shift amount received from control server 1102 (ST1207).

Note that the PHS control channel receiver-equipped base station 1105 may directly notify the base station 1103 of the timing shift amount without going through the control server 1102. In this case, the base station 1103 may shift the transmission timing based on the timing shift amount notified without going through the control server 1102.

FIG. 13 is a configuration diagram of a base station equipped with a PHS control channel receiver according to Embodiment 3 of the present disclosure. The base station 1105 equipped with a PHS control channel receiver includes an antenna 1301, a transmitting/receiving section 1302, a PHS frame timing detecting section 1303, a timing shift amount calculating section 1304, a network section 1305, and a frame timing controlling section 1306. .

Transmission/reception section 1302 receives PHS and TD-LTE signals via antenna 1301. PHS frame timing detection section 1303 receives the PHS frame at the frequency of the PHS control channel received by transmitting/receiving section 1302, and detects PHS frame timing based on the received PHS frame. The timing shift amount calculation unit 1304 calculates the timing shift amount of TD-LTE based on the PHS frame timing detected by the PHS frame timing detection unit 1303. The network unit 1305 is connected to a network and transmits the timing shift amount calculated by the timing shift amount calculation unit 1304 to the control server 1102 or the TD-LTE base station via the network. The frame timing control unit 1306 receives the timing shift amount via the network unit 1305, and controls the frame timing (ie, transmission timing) of TD-LTE.

FIG. 14 is a configuration diagram of a control server when using a base station equipped with a PHS control channel receiver according to Embodiment 3 of the present disclosure. The control server 1102 includes a network section 1401 and a timing shift amount determining section 1402.

The network unit 1401 is connected to a network and transmits and receives data via the network. The timing shift amount determining unit 1402 determines the timing shift amount of TD-LTE based on the timing shift amount received via the network unit 1401, and transmits the timing shift amount to the base station 1103 and PHS control via the network unit 1401. The channel is transmitted to the base station 1105 equipped with a channel receiver. Here, the timing shift amount determination unit 1402 may simply notify the other base stations 1103 of the timing shift amount received from the PHS control channel receiver equipped base station 1105, or may receive different timing shift amounts from a plurality of base stations. If notified, the timing shift amount may be uniquely determined.

As explained above, according to the third embodiment, the PHS control channel receiver only needs to be installed in one base station, and only the base station equipped with the PHS control channel receiver detects the PHS frame timing. Based on the results, inter-base station synchronization between the PHS base station and the TD-LTE base station can be realized.

Note that the TD-LTE base station described in Embodiment 1 may include part or all of the configuration of the base station equipped with the PHS control channel receiver described in Embodiment 3 using FIG. 13 etc. good.

(Embodiment 4)
Embodiment 4 according to the present disclosure will be described using FIGS. 15 to 18.

FIG. 15 is a diagram illustrating a method of notifying a transmission timing shift amount by a TD-LTE timing shift amount measuring device according to Embodiment 4 of the present disclosure.

In FIG. 15, a control server 1502 is connected to a timing shift amount measuring device 1501, a plurality of PHS base stations 1504, 1506, 1508, 1510, and a plurality of TD-LTE base stations 1503, 1505, 1507, 1509. The timing shift amount measuring device 1501 detects the timing of the PHS frame at the PHS control channel frequency, calculates the shift amount of the transmission timing of the TD-LTE base stations 1503, 1505, 1507, and 1509, and calculates the calculated timing shift amount. Send to control server 1502. The control server 1502 determines the timing shift amount based on the timing shift amount received from the timing shift amount measuring device 1501, and transmits the determined timing shift amount to each TD-LTE base station 1503, 1505, 1507, and 1509. .

As a method for calculating the amount of shift in the transmission timing of a TD-LTE base station, as shown in FIG. The amount of shift in the transmission timing of the LTE base station may be calculated, and the amount of timing shift may be notified to each TD-LTE base station 1503, 1505, 1507, and 1509 via the control server 1502.

FIG. 16 is a sequence diagram showing operations between a timing shift amount measuring device, a base station, and a control server according to Embodiment 4 of the present disclosure. FIG. 16 explains the operation of the fourth embodiment whose configuration is explained in FIG. 15.

Timing shift amount measuring device 1501 receives a PHS frame at the PHS control channel frequency and detects the timing of the PHS frame (ST1601). Next, the timing shift amount measuring device 1501 calculates the TD-LTE timing shift amount based on the detected PHS frame timing (ST1602). Next, the timing shift amount measuring device 1501 transmits the calculated timing shift amount to the control server 1502 (ST1603).

Control server 1502 transmits the timing shift amount received from timing shift amount measuring device 1501 to base station 1503 (ST1604).

Base station 1503 shifts the transmission timing of base station 1503 based on the timing shift amount received from control server 1502 (ST1605).

FIG. 17 is a configuration diagram of a base station according to Embodiment 4 of the present disclosure. FIG. 17 explains the configuration of the TD-LTE base station 1503 of the fourth embodiment described in FIG. 15. The base station 1503 includes an antenna 1701, a transmitting/receiving section 1702, a frame timing control section 1703, and a network section 1704.

Transmission/reception section 1702 transmits and receives signals via antenna 1701. Frame timing control section 1703 controls the transmission timing of base station 1503 based on the timing shift amount received via transmission/reception section 1702. A network unit 1704 communicates with other devices via a network.

FIG. 18 is a configuration diagram of a timing shift amount measuring device according to Embodiment 4 of the present disclosure. FIG. 18 explains the configuration of the timing shift amount measuring device of the fourth embodiment whose configuration was explained in FIG. 15. The timing shift amount measuring device 1501 includes an antenna 1801, a transmitting/receiving section 1802, a PHS frame timing detecting section 1803, a timing shift amount calculating section 1804, and a network section 1805.

The transmitting/receiving unit 1802 receives PHS frames at the PHS control channel frequency via the antenna 1801. PHS frame timing detection section 1803 detects PHS frame timing based on the PHS frame received from transmission/reception section 1802. The timing shift amount calculation unit 1804 calculates the TD-LTE timing shift amount based on the detected PHS frame timing. The network unit 1805 transmits the calculated timing shift amount to the control server 1502 via the network.

As explained above, according to the fourth embodiment, each base station does not require a PHS control channel receiver, but by connecting a timing shift amount measuring device equipped with a PHS control channel receiver to a control server. , the timing shift amount measuring device detects the frame timing of the PHS, and calculates the timing shift amount based on the result. Then, the timing shift amount measuring device notifies the TD-LTE base station of the calculated timing shift amount via the control server, thereby realizing inter-base station synchronization between the PHS base station and the TD-LTE base station. Can be done.

Note that the TD-LTE base station described in Embodiment 1 may include part or all of the configuration of the TD-LTE base station described in Embodiment 4 using FIG. 17 and the like.

(Embodiment 5)
Embodiment 5 according to the present disclosure will be described using FIGS. 19 to 24.

FIG. 19 is a diagram illustrating an example of residual interference from the TD-LTE system to the PHS system according to Embodiment 5 of the present disclosure.

In the 3GPP standard, in the TD-LTE frame format, data channels that transmit and receive downlink or uplink data can temporarily stop transmission and reception as described above. On the other hand, according to the 3GPP standard, transmission of broadcast channels for transmitting system information, synchronization channels for synchronization, downlink control channels, reference signals, etc. cannot be stopped. Therefore, if the TD-LTE base station complies with the 3GPP standard, even if the scheduling of downlink and uplink data channels is avoided using the slot timing of the PHS control channel using the method of Embodiment 1, Such a TD-LTE control channel cannot be stopped. Therefore, interference with the PHS control channel caused by the transmission power of channels other than user data, such as the TD-LTE control channel, which cannot be stopped according to the standard remains, and further countermeasures are required.

Referring to FIG. 19, the PHS frame 1901 includes four transmission frames Tx1, Tx2, Tx3, Tx4 and four reception frames Rx1, Rx2, Rx3, Rx4, and the PHS frame length 1906 is 5 ms.

When transmitting the TD-LTE frame 1904, it is possible to stop transmitting the downlink data channel 1908 among the TD-LTE subframes consisting of the control channel 1907 and the data channel 1908, but it is possible to stop the transmission of the downlink data channel 1908, In this case, transmission of the TD-LTE control channel 1907 cannot be stopped. Therefore, residual interference 1905 may occur between the TD-LTE transmission power 1903 of the TD-LTE control channel 1907 and the PHS transmission power 1902 of Tx1 of the PHS frame 1901.

FIG. 20 is a diagram showing residual interference to a PHS terminal located immediately below a TD-LTE base station according to Embodiment 4 of the present disclosure. As shown in FIG. 20, when the TD-LTE base station 2002 is installed away from the PHS base station 2001 on a ceiling 2003 or the like, the PHS terminal 2006 located directly below the TD-LTE (sXGP) base station 2002 The power of the residual interference signal 2004 from the LTE base station 2002 is relatively larger than the power of the desired signal 2005 from the PHS base station. By installing the TD-LTE base station 2002 close to the PHS base station 2001, the ratio of residual interference power to desired signal power can be reduced. However, if the TD-LTE base station 2002 cannot be installed close to the PHS base station 2001 due to restrictions on the installation location, the power of the residual interference signal 2004 increases.

FIG. 21 is a diagram illustrating the effect of reducing transmission power of a control channel, etc. of a TD-LTE base station and the resulting interference reduction according to Embodiment 5 of the present disclosure. When the transmission timings of the PHS downlink control channel and TD-LTE control channel overlap, etc., interference between the PHS and TD-LTE can be reduced by reducing the transmission power of the TD-LTE base station. If possible, reduce the transmission power of the TD-LTE base station as shown in FIG. This makes it possible to reduce the residual interference described in FIG. 20. The vertical axis in the upper diagram of FIG. 21 represents PHS transmission power 2101, and the horizontal axis represents time. The vertical axis in the lower diagram of FIG. 21 represents TD-LTE transmission power 2102, and the horizontal axis represents time. For example, the residual interference can be reduced by lowering the TD-LTE transmission power 2102 in FIG. 21 by the power reduction 2103 from the TD-LTE transmission power 1903 described in FIG. 19. In other words, the effect of interference reduction 2104 can be obtained.

Similar to Embodiment 1, FIG. 22 is a diagram illustrating received power after combining PHS control channels measured at a TD-LTE base station according to Embodiment 5 of the present disclosure. As shown in FIG. 22, the smaller the received power P _{phs_rx [dBm] is with respect to the maximum power P phs_rx [} dBm] 2202, the more the received power 2201 after combining the PHS control channels measured at the TD-LTE base station, the more TD-LTE It can be determined that the base station is far from the PHS base station. If the transmission power of a TD-LTE base station that can coexist when a TD-LTE base station is installed with a distance between base stations of a PHS base station = 0 (m) is P _{lte_tx_max} [dBm], then the TD-LTE base station The transmission power of the TD-LTE base station is reduced from P _{lte_tx_max} [dBm] in accordance with the maximum received power P _{phs_rx} [dBm] of the PHS control channel measured in .

Specifically, the path loss difference L=(L _phs - L _lte ) found from the path loss L _phs from the PHS base station and the path loss L _lte from the TD-LTE base station at a point directly below the TD-LTE base station is calculated as the received power. Uniquely estimate from P _{phs_rx} and reduce the transmit power by L from P _{lte_tx_max} .

FIG. 23 is a flow diagram of the operation of the base station according to Embodiment 5 of the present disclosure. TD-LTE base station 2002 measures the received power of the signal at the PHS control channel frequency (ST2301). Next, TD-LTE base station 2002 estimates the path loss difference from the received power (ST2302). Next, TD-LTE base station 2002 calculates the transmission power of the TD-LTE base station based on the estimated path loss difference (ST2303). Based on the calculated transmission power, the transmission power of channels that cannot be stopped according to standards, such as a broadcast channel for transmitting system information of the TD-LTE base station, a synchronization channel for synchronization, and a downlink control channel, is controlled.

FIG. 24 is a configuration diagram of a base station according to Embodiment 5 of the present disclosure. The base station 2002 includes an antenna 2401, a transmitting/receiving section 2402, a received power measuring section 2403, a path loss difference estimating section 2404, and a transmit power controlling section 2405.

The transmitting/receiving unit 2402 transmits and receives PHS and TD-LTE signals via the antenna 2401. Received power measuring section 2403 estimates the received power of the PHS control channel received by transmitting/receiving section 2402. Path loss difference estimating section 2404 estimates a path loss difference based on the estimated received power received from received power measuring section 2403. Transmission power control section 2405 calculates the transmission power of base station 2002 based on the estimated path loss difference.

As explained above, according to the fifth embodiment, residual signals from channels that cannot be stopped according to standards, such as broadcast channels for transmitting system information of TD-LTE base stations, synchronization channels for synchronization, and downlink control channels, Interference can be reduced.

Note that the TD-LTE base station described in Embodiments 1 to 4 may include part or all of the configuration of the base station described in Embodiment 5 using FIG. 24 and the like.

<Summary of this disclosure>
The base station in the present disclosure provides a second communication method using a second communication method that uses a second frequency band that is common to a part of the first frequency band used in the first communication method used in the first communication system. A base station of the system includes an estimator that estimates slot timing of a downlink control channel transmitted from the base station of the first communication system at a predetermined channel frequency and a predetermined period; In the resources of the second communication method that correspond to the slot timing on the time axis, a scheduling unit that performs scheduling to allocate data to resource blocks that do not overlap with the predetermined channel frequency, and a transmitting and receiving unit that performs transmission and reception based on the scheduling. and.

The estimating unit of the base station of the present disclosure is configured to use a slot after a predetermined number of slots of the downlink control channel as an uplink control channel transmitted from the terminal of the first communication system using the predetermined channel frequency and the predetermined period. The scheduling unit performs scheduling to allocate data to resource blocks that do not overlap with the predetermined channel frequency in resources that correspond in the time axis to the slot timing of the uplink control channel.

The base station of the present disclosure includes a received power measuring unit that measures the received power of a signal transmitted from the base station of the first communication system at the predetermined channel frequency, and a received power measuring unit that measures the received power of the signal that is divided at each predetermined period. , a received power combining unit that combines the combined received power with the leading timing, and the estimating unit estimates the transmission period of the downlink control channel based on the magnitude relationship between the combined received power and a threshold.

The certain period of time of the base station of the present disclosure is an integral multiple of the predetermined period.

The base station of the present disclosure includes a path loss difference estimator that estimates a path loss difference based on a difference between a maximum received power and a received power of a signal transmitted from the base station of the first communication system; The apparatus further includes a transmission power control section that controls transmission power.

The base station of the present disclosure performs transmission power control based on the path loss difference on at least one of a broadcast channel through which system information is transmitted in the second communication method, a synchronization channel for synchronization, a downlink control channel, and a reference signal. Performed against.

The base station of the present disclosure provides power information indicating received power measured at a predetermined channel frequency at which a downlink control channel is transmitted from the base station of the first communication system to a control station connected to the base station. A transmitting network unit and the network unit receive the timing shift amount of the second communication method from the control station, and the received timing shift amount of the second communication method is transmitted by the control station to the second communication method. combining the received power information based on the frame timing of the first communication system, detecting the frame timing of the first communication system based on the combined power information, and detecting the frame timing of the first communication system based on the detected frame timing of the first communication system. and a frame timing control unit that shifts the transmission timing according to the received timing shift amount.

The first communication method of the base station of the present disclosure is a PHS (Personal Handy-phone System) method, and the second communication method is an sXGP (shared eXtended Global Platform) method.

The control station of the present disclosure provides a second communication system that uses a second communication method that uses a second frequency band that is common to a part of the first frequency band that is used in the first communication method that is used in the first communication system. A control station connected to a plurality of base stations of a system, the received power measured from each of the plurality of base stations at a predetermined channel frequency at which a downlink control channel is transmitted from the base station of the first communication system. a network unit that receives power information indicating a frame timing of the first communication method; and a frame that combines the plurality of power information based on the frame timing of the second communication method and detects the frame timing of the first communication method based on the combined power information. a timing detection unit, and calculates a timing shift amount of the second communication method based on the frame timing of the first communication method, and transmits the timing shift amount to each of the plurality of base stations via the network unit. and a timing shift amount calculation unit.

The base station of the present disclosure provides a second communication method using a second communication method that uses a second frequency band that is common to a part of the first frequency band used in the first communication method used in the first communication system. A base station of the system receives frames of the first communication method at a predetermined channel frequency at which a downlink control channel is transmitted from the base station of the first communication system, and detects frame timing of the first communication method. a timing shift amount calculation section that calculates a timing shift amount of the second communication method based on the frame timing of the first communication method, and a base of another second communication system via a network. The apparatus includes a network section that transmits the timing shift amount to the station, and a frame timing control section that shifts the transmission timing according to the timing shift amount.

The timing shift amount measuring device of the present disclosure uses a second communication method that uses a second frequency band that is common to a part of the first frequency band used in the first communication method used in the first communication system. A timing shift amount measuring device connected to a control station connected to a plurality of base stations of a second communication system, wherein the timing shift amount measuring device a frame timing detection unit that receives frames of a communication method and detects frame timing of the first communication method; and a timing shifter that calculates a timing shift amount of the second communication method based on the frame timing of the first communication method. and a network unit that transmits the timing shift amount to the control station or the plurality of base stations via a network.

The communication method of the present disclosure includes a second communication method using a second communication method that uses a second frequency band that is common to a part of the first frequency band used in the first communication method used in the first communication system. A communication method for a base station of a system, the timing of a slot of a downlink control channel transmitted from a base station of the first communication system at a predetermined channel frequency and a predetermined period is estimated, and the timing of a slot of a downlink control channel transmitted from the base station of the first communication system is estimated. In the resources of the second communication method that correspond to the slot timing on the time axis, scheduling is performed to allocate data to resource blocks that do not overlap with the predetermined channel frequency, and transmission and reception are performed based on the scheduling.

The present disclosure can be implemented with software, hardware, or software in conjunction with hardware.

Each functional block used in the description of the above embodiment is partially or entirely realized as an LSI that is an integrated circuit, and each process explained in the above embodiment is partially or entirely realized as an LSI, which is an integrated circuit. It may be controlled by one LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. The LSI may include data input and output. LSIs are sometimes called ICs, system LSIs, super LSIs, and ultra LSIs depending on the degree of integration.

The method of circuit integration is not limited to LSI, but may be implemented using a dedicated circuit, a general-purpose processor, or a dedicated processor. Furthermore, an FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used. The present disclosure may be implemented as digital or analog processing.

Furthermore, if an integrated circuit technology that replaces LSI emerges due to advancements in semiconductor technology or other derived technology, then of course the functional blocks may be integrated using that technology. Possibilities include the application of biotechnology.

The present disclosure is applicable to, for example, a base station, a control station, a timing shift amount measuring device, and a communication method.

201 TD-LTE base station 202 PHS base station 203 TD-LTE base station 204 PHS base station 205 TD-LTE base station 206 PHS base station 501 Antenna 502 Transmission/reception section 503 Received power measuring section 504 Received power combining section 505 PHS control channel timing Estimation unit 506 Scheduling unit 507 Data processing unit 701 Control server 721 TD-LTE base station 722 PHS base station 723 TD-LTE base station 724 PHS base station 725 TD-LTE base station 726 PHS base station 727 TD-LTE base station 728 PHS Base station 901 Antenna 902 Transmission/reception section 903 Received power measurement section 904 Received signal synthesis section 905 Network section 906 Frame timing control section 1001 Network section 1002 PHS frame timing detection section 1003 Timing shift amount calculation section 1102 Control server 1103 TD-LTE base station 1104 PHS base station 1105 PHS control channel receiver equipped base station 1106 PHS base station 1107 TD-LTE base station 1108 PHS base station 1109 TD-LTE base station 1110 PHS base station 1301 Antenna 1302 Transmission/reception section 1303 PHS frame timing detection section 1304 Timing shift Amount calculation section 1305 Network section 1306 Frame timing control section 1401 Network section 1402 Timing shift amount determination section 1501 Timing shift amount measuring device 1502 Control server 1503 TD-LTE base station 1504 PHS base station 1505 TD-LTE base station 1506 PHS base station 1507 TD-LTE base station 1508 PHS base station 1509 TD-LTE base station 1510 PHS base station 1701 Antenna 1702 Transmission/reception section 1703 Frame timing control section 1704 Network section 1801 Antenna 1802 Transmission/reception section 1803 PHS frame timing detection section 1804 Timing shift amount calculation section 1805 Network section 2001 PHS base station 2002 TD-LTE base station 2006 PHS terminal 2401 Antenna 2402 Transmission/reception section 2403 Reception power measurement section 2404 Path loss difference estimation section 2405 Transmission power control section

Claims (7)

A base station of a second communication system using a second communication method that uses a second frequency band that is common to a part of the first frequency band used in the first communication method used in the first communication system, ,
an estimator that estimates slot timing of a downlink control channel transmitted from a base station of the first communication system at a predetermined channel frequency and a predetermined period;
a scheduling unit that performs scheduling to allocate data to resource blocks that do not overlap with the predetermined channel frequency in resources of the second communication method that correspond in time to the estimated slot timing of the downlink control channel;
a transmitting/receiving unit that performs transmission and reception based on the scheduling;
Equipped with
The estimation unit estimates a slot after a predetermined number of slots after the slot of the downlink control channel as the timing of the slot of the uplink control channel transmitted from the terminal of the first communication system using the predetermined channel frequency and the predetermined cycle. death,
The scheduling unit performs scheduling to allocate data to resource blocks that do not overlap with the predetermined channel frequency in resources that correspond in the time axis to slot timing of the uplink control channel.
base station. a received power measurement unit that measures received power of a signal transmitted from a base station of the first communication system at the predetermined channel frequency;
a received power combining unit that combines each of the received powers divided into a certain period that is an integral multiple of a predetermined cycle , with the leading timing aligned;
further comprising;
The estimation unit estimates a transmission period of the downlink control channel based on a magnitude relationship between the combined received power and a threshold.
The base station according to claim 1 . Based on the difference between the maximum received power of the control channel of the base station of the first communication system measured at the base station of the second communication system and the received power of the signal transmitted from the base station of the first communication system. a path loss difference estimator that estimates a path loss difference;
a transmission power control unit that controls transmission power based on the path loss difference;
further comprising;
The base station according to claim 2 . Performing transmission power control based on the path loss difference on at least one of a broadcast channel for transmitting system information in the second communication method, a synchronization channel for synchronization, a downlink control channel, and a reference signal.
The base station according to claim 3 . a network unit that transmits power information indicating received power measured at a predetermined channel frequency at which a downlink control channel is transmitted from the base station of the first communication system to a control station connected to the base station;
The network unit receives a timing shift amount of the second communication method from the control station,
The received timing shift amount of the second communication method is determined by the control station combining the received power information based on the frame timing of the second communication method, and adjusting the timing shift amount of the first communication method based on the combined power information. The frame timing of the first communication method is detected and calculated based on the detected frame timing of the first communication method,
a frame timing control unit that shifts transmission timing according to the received timing shift amount;
The base station according to claim 1 , further comprising: The first communication method is a PHS (Personal Handy-phone System) method,
The second communication method is an sXGP (shared eXtended Global Platform) method.
The base station according to claim 1 . A communication method of a base station of a second communication system using a second communication method that uses a second frequency band that is common to a part of the first frequency band used in the first communication method used in the first communication system. And,
estimating the timing of a slot of a downlink control channel transmitted from a base station of the first communication system using a predetermined channel frequency and a predetermined period;
performing scheduling to allocate data to resource blocks that do not overlap with the predetermined channel frequency in the resources of the second communication method that correspond on the time axis to the estimated slot timing of the downlink control channel;
Transmitting and receiving based on the scheduling,
In the estimation, a slot after a predetermined number of slots after the slot of the downlink control channel is estimated as the timing of the slot of the uplink control channel transmitted from the terminal of the first communication system using the predetermined channel frequency and the predetermined period. ,
In the scheduling, in resources corresponding in the time axis to slot timing of the uplink control channel, scheduling is performed to allocate data to resource blocks that do not overlap with the predetermined channel frequency.
Communication method.

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